The purpose of this system is to permit entrance to a facility under construction or remodeling by specific construction personnel and thereafter restrict their entrance. This means is commonly referred to as construction keying.
In application, the management supplies to the construction worker, a specially cut key. This key will operate a specific combination lock only when a device called an "insert" has been previously placed in the keyway of the lock. Installation of the insert would normally be installed in the factory but can also be field installed. The owner at its will can extract the insert from the lock, thereby disabling the worker's key. This is accomplished by a unique tool called the Insertion/Extraction Tool. Upon completion of the work, the owner would remove the insert and supply his designated occupants with a regular change key to operate the lock.
The economical and easy-to-install system of the present invention does not take away any master key combinations or limit any other special features effecting normal keying practices.